Search found 176 matches

by SteveBagley
Sun Aug 30, 2015 8:37 am
Forum: Chat forum [ENG]
Topic: Why Falcon has 16 bit RAM bus?
Replies: 10
Views: 6656

Re: Why Falcon has 16 bit RAM bus?

one thing bother me regarding theory that Falcon design start as "some add-ons and a DSP on a daughter card" - how they could implement Videl on ST design? Videl need access to RAM at 32bits. This is not possible to do if you just put daughter card on ST. right? Two things, one they proba...
by SteveBagley
Wed Jul 29, 2015 9:46 am
Forum: Hardware
Topic: THE FOUR STBOOKS repairs
Replies: 162
Views: 41485

Re: THE FOUR STBOOKS repairs

Simbo, have you seen this interview with Tracy Hall from 1992 before? There's some interesting comments on the ST Book's memory and power saving features that might be useful for you. I did things to save five milliamps here and three percent there; for example, we used a new RAM-refresh scheme to s...
by SteveBagley
Thu Jul 16, 2015 1:25 pm
Forum: Steem
Topic: steem fails to load tos2.08
Replies: 5
Views: 6133

Re: steem fails to load tos2.08

I've loaded and run (the english) TOS 2.08 using Hatari on my Mac without issue. It requires the screen to be set to be Mono otherwise the display is corrupt (and, of course, requires an IDE HDD or it'll bomb on boot). I'd be wary running it in anything but 4MB mode too since the ST Book doesn't do ...
by SteveBagley
Thu Jul 02, 2015 3:33 pm
Forum: Hardware
Topic: Video address counter in STE
Replies: 3
Views: 1613

Re: Video address counter in STE

How often in this incremented? For every word fetched, or every fourth word? Just done a little test on my MegaSTE (see code below) and am seeing various differences of address but both 2 and 6 are seen so I'd guess it is updated every word (it'd make sense since the MCU needs to put every word add...
by SteveBagley
Mon Jun 15, 2015 2:14 pm
Forum: 680x0
Topic: Quake 2 on Falcon030
Replies: 1208
Views: 307753

Re: Quake 2 on Falcon030

- Maybe ditch the Blitter to save a few pennies. It isn't very useful. BLiTTER is rather simple therefore cheap. Saving would be small and the compatibility would decrease. And finally you can do a nice things with it like gouraud shading and it can works in parallel with the CPU One thing Atari co...
by SteveBagley
Thu May 07, 2015 11:04 pm
Forum: Chat forum [ENG]
Topic: Atari Sparrow ?
Replies: 17
Views: 8240

Re: Atari Sparrow ?

If I remember right doesn't the Sparrow load VDI from the hard disk?

Also there's no ram card on that machine.

Steve
by SteveBagley
Thu Mar 19, 2015 2:30 pm
Forum: 680x0
Topic: Quake 2 on Falcon030
Replies: 1208
Views: 307753

Re: Quake 2 on Falcon030

Yep that's correct - but sure, if anyone notices 030 optimizations then punt them in my direction :) Part of the reason for posting code - to make sure I don't miss things (forest vs trees and all that!). The one thing that I wondered about is whether you can increase the code density in the cache ...
by SteveBagley
Fri Mar 06, 2015 1:21 am
Forum: Applications
Topic: Best environment for 4MB STE
Replies: 13
Views: 6578

Re: Best environment for 4MB STE

It's not MagiC that's the problem but rather the way Hatari attempts to patch tos to provide shared folder support not working with MagiC (someone would need to write an XFS to do it properly).

Steve
by SteveBagley
Mon Feb 23, 2015 1:13 pm
Forum: MiST
Topic: Acorn Archimedes
Replies: 228
Views: 64269

Re: Acorn Archimedes

This machine didn't have a great number of games developped for it : http://en.wikipedia.org/wiki/Category:Acorn_Archimedes_games But there's a few to try. I tried a few games : for example Nebulus, Pac-Mania and the Lemmings series (contrarily to the DOS version, passwords are easier to note and r...
by SteveBagley
Sun Feb 22, 2015 10:31 pm
Forum: Hardware
Topic: Analogic TOS switch won't fit, and TOS 2.06 fail to boot
Replies: 9
Views: 2152

Re: Analogic TOS switch won't fit, and TOS 2.06 fail to boot

Not sure on the resistors, but the circuit diagram might give some clues. As for the switcher, have you tried putting some sockets into the sockets to space the switcher above the DMA, although that might collide with the floppy above it?

Steve
by SteveBagley
Wed Feb 18, 2015 5:36 pm
Forum: Chat forum [ENG]
Topic: Atari ST on YouTube
Replies: 21
Views: 8559

Atari ST on YouTube

Part 2 of the video is up…

http://youtu.be/3OdtfsXOkEY
by SteveBagley
Mon Feb 16, 2015 7:29 pm
Forum: Chat forum [ENG]
Topic: Atari ST on YouTube
Replies: 21
Views: 8559

Re: Atari ST on YouTube

calimero wrote:I also did not know that it is you channel! (I am already subscribed to your channel! :) great channel)


Not my channel, its run by Sean Riley and Brady Haran -- I just keep appearing on it and suggesting people/topics, however a lot of the people on it are from my department.

Steve
by SteveBagley
Mon Feb 16, 2015 3:17 pm
Forum: Chat forum [ENG]
Topic: Atari ST on YouTube
Replies: 21
Views: 8559

Re: Atari ST on YouTube

I did not have clue that it is you! (I searched for "atari st" in past month on google!) Great videos, I watched video about Mac classic and I will check your video that you suggested! Glad you liked it -- Computerphile is a nice adjunct to my day job (CS lecturer) even though I'd much pr...
by SteveBagley
Mon Feb 16, 2015 9:20 am
Forum: Chat forum [ENG]
Topic: Atari ST on YouTube
Replies: 21
Views: 8559

Re: Atari ST on YouTube

calimero wrote:quite new one!

Atari ST: Accidental Musical Workhorse - Computerphile

https://www.youtube.com/watch?v=O4kf1Wbaruo (10 min)


:-)

We couldn't let the 30tn anniversary pass unmarked -- you might want to watch the one I did on kernel panics as well though…

http://youtu.be/nr9auoHtvzM

Steve
by SteveBagley
Thu Feb 12, 2015 4:08 pm
Forum: Coding
Topic: OBJECT tree / objc_draw and object tree lifecycle
Replies: 16
Views: 4900

Re: OBJECT tree / objc_draw and object tree lifecycle

I think it would be more accurate to say it was designed to be sufficient for a different style of UI. Windows were purely to contain documents and so would only ever need to redrawing by the user using the VDI. Forms were modal, so objc_draw and form_do don't need to keep track of the OBJECTs they ...
by SteveBagley
Fri Feb 06, 2015 3:07 pm
Forum: Chat forum [ENG]
Topic: Shiraz Shivji
Replies: 4
Views: 3359

Shiraz Shivji

Just being interviewed about the ST for the YouTube channel Computerphile -- anyone know how to pronounce Shiraz Shivji's name correctly?

Steve
by SteveBagley
Fri Feb 06, 2015 11:27 am
Forum: Hardware
Topic: 4MB Upgrade & 16MHz Booster progress
Replies: 721
Views: 128363

Re: 4MB Upgrade & 16MHz Booster progress

So has anyone else run into problems with PLCC ROMs ?? This has got me stumped as there shouldn't be any difference from using 2 8bit ROMs to a single 16bit ROM :roll: Well the Falcon and ST Book both used 16bit ROM chips without issue so you can rule that out as an issue. At a guess, I suspect you...
by SteveBagley
Mon Feb 02, 2015 11:04 pm
Forum: Hardware
Topic: Need help with initial faultfinding on 1040STe
Replies: 41
Views: 10863

Re: Need help with initial faultfinding on 1040STe

I used a cheap £10 logic analyser from Amazon on an ST (not E) earlier to find out what was going on as I could see when various things happened and cross-reference it to the TOS source. Just watching DTACK, AS, A23, BERR and a few other bits was enough, see my thread elsewhere, might be harder with...
by SteveBagley
Sat Jan 24, 2015 12:39 am
Forum: Hardware
Topic: Dead(ish) STM - Now undead
Replies: 17
Views: 1965

Re: Dead(ish) STM

Colour or mono monitor? I'm guessing the latter as it sounds similar to the problems I was having with an STm (see http://www.atari-forum.com/viewtopic.php?f=15&t=27414 ). The output on the serial line suggests a bit error in RAM, I've found if this happens early enough and in the wrong places i...
by SteveBagley
Fri Jan 16, 2015 7:01 pm
Forum: Hardware
Topic: Repairing an old 520STm
Replies: 16
Views: 3188

Re: Repairing an old 520STm

Progress -- I have seen the desktop… Briefly as it reset and a lot of bombs most of the time. I desoldered the RAM chips yesterday from the motherboard and today attached two 512k SIMMS (which have been lieing around the house since I upgraded my STe in the 1990s!) using some SIMMS sockets I grabbed...
by SteveBagley
Thu Jan 15, 2015 2:19 pm
Forum: Hardware
Topic: Repairing an old 520STm
Replies: 16
Views: 3188

Re: Repairing an old 520STm

Have you got the copy of ST Internals with the TOS listing in the back? I spent many hours single stepping hardware through that code, and yes it uses BERR to work out the memory size. That's exactly what I'm using as reference :) (well a PDF of it as my paper copy is long gone now :( ). The proble...
by SteveBagley
Wed Jan 14, 2015 11:43 pm
Forum: Hardware
Topic: Repairing an old 520STm
Replies: 16
Views: 3188

Re: Repairing an old 520STm

hmmm, everytime the /AS is asserted means there is a new address being floated or making the address valid, and the /Dtack should be in that cycle, towards begining of State 7, well depends if its a Read or Write Cycle. To make it easier to decode, capture the /DTack I've done that previously and D...
by SteveBagley
Wed Jan 14, 2015 10:31 am
Forum: Hardware
Topic: Need help with 72 pin SIMM RAM upgrade
Replies: 12
Views: 1369

Re: Need help with 72 pin SIMM RAM upgrade

Can you upload a photo? It's actually worse than it looks like in this photo. The errors are not constant, but flickers. As you can see they are evenly spaced, every 8th word has problems. The problem is only in the extra RAM - if I disable it by disconnecting the RAS/CAS lines there are no problem...
by SteveBagley
Tue Jan 13, 2015 10:02 pm
Forum: Hardware
Topic: Need help with 72 pin SIMM RAM upgrade
Replies: 12
Views: 1369

Re: Need help with 72 pin SIMM RAM upgrade

joska wrote:dit 2: I disconnected A9 and grounded it to limit the upper bank to 512Kb in case there was a problem with the MMU. Still a problem, but the pattern changed. Now the random errors were concentrated on five evenly spaced columns.


Can you upload a photo?

Steve
by SteveBagley
Tue Jan 13, 2015 8:06 pm
Forum: Hardware
Topic: 4MB Upgrade & 16MHz Booster progress
Replies: 721
Views: 128363

Re: 4MB Upgrade & 16MHz Booster progress

It would work, though there is a bit more going on with the 32mhz clock which I don't fully get. http://www.exxoshost.co.uk/atari/last/16mhz/index.htm Scroll down to March 27, 2014 UPDATE . Yea that's circuits ensuring that the subcarrier, Hsync and the pixel-clock are such so you don't get dot-cra...

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